Influence of Re Concentration on the Mechanical Properties of Tungsten Borides from First-Principles Calculations

Tungsten borides are promising high-temperature materials. However, the structure and hardening mechanisms of tungsten boride are still great challenges. To solve the problems, we apply the first-principles method to study the structure of WB3 and explore the influence of alloying element Re on the mechanical properties of WB3. The calculated Vickers hardness of WB3 is 39.1 GPa. We further find that a low concentration of Re can improve the hardness of WB3, which is in good agreement with the experimental result. However, the hardness and elastic properties of WB3 decrease gradually with increasing Re concentration. The calculated results show that the structure and hardness of WB3 are attributed to the B–B hexagonal prism. A high concentration of Re weakens the charge interaction between the B–B atoms, and reduces the mechanical properties of WB3. Therefore, we can adjust the alloy concentration to improve the Vickers hardness of transition metal borides.